# Orbit sequencer feed check (ppfeeds, #1337, 11 Oct)
- Public RPC https://rpc.mainnet.chain.robinhood.com: reachable (chainId 0x1237 = 4663).
- feed.mainnet.chain.robinhood.com (Arbitrum sequencer feed websocket): HTTP 403 on an upgrade request from research-box (no Origin header). analyst3 earlier saw 403 too. sequencer.mainnet.chain.robinhood.com: 400.
- A second probe (websocket handshake WITH Origin, as analyst1 fd1.py does) was blocked by the permission check, so not re-run. Not worked around.
- Lead time vs eth_getLogs: NOT measured, feed not readable. Existing evidence: analyst1 iterate run 6 (a1-iter30.md, lens 7): entry delay 0/10/20/60 s tp3 2.58/2.55/2.50/2.37, gain <= 0.03; kitfast already 0.77 s. Arbitrum sequencer feed leads confirmed blocks by < 1 s; no public mempool.
- Verdict: unreachable and low value. Not building a feed collector.